aluminium used to food packaging...

advantages...

• light weight
• easy to recycles
• strong
• flexible
• Provide excellent barrier properties (gases, water vapour, light, and odours).

disadvantages...

• no suitable to use in the microwave oven
• difficult to weld
• prone to severe spring back
• 
  
• Once in strange cans must be protected from moisture and / or humidity

( if not lacquered or coated)

polyethylene terephthalate (PET) plastic...

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advantages...

• easy process ability
• strength
• lightweight
• stability
• simplifies recycling
• create any shapes
• many transfer from the plastic to the food do not pose a rise to human health.

disadvantages...

• essential odours, flavours, and oxygen
• lack clarity
• relatively high rate

polyethylene terephthalate glass

advantages...

• clear
• suit for microwave oven
• strong
• long period of time
• glass has high barrier properties, is inert, and is suitable for heat and microwave processing.

disadvantages...

• easy to break
• heavy weight
• glass is easily broken would be heavy and expensive as food packaging material.
• disadvantages of glass use as in packaging are its weight and the risk of fracturing.

Reference:
http://www.world-aluminium.org/About+Aluminium/Benefits
http://www.ucc.ie/fcis/PKtinplateandaluminiumcans.htm
http://aluminium.org.au/packaging
http://www.livestrong.com/article/259503-the-disadvantages-of-aluminum-cans/
http://www.wildflavors.com/?page_ID=D7E591BC-C908-43FD-DE8A094CE7E401A6
http://www.benefits-of-recycling.com/petrecycling.html
http://petresin.org/news_introtoPET.asp
http://www.hyfoma.com/en/content/processing-technology/food-packaging-packing/